1. Field
The invention relates to solid electrolytes for rechargeable lithium batteries and rechargeable lithium batteries including the same.
2. Description of Related Art
Rechargeable lithium batteries have recently been spotlighted as energy sources for small, portable electronic devices. A rechargeable lithium battery includes a positive electrode, a negative electrode, and an electrolyte.
As the positive active material of a rechargeable lithium battery, lithium-transition element composite oxides capable of intercalating lithium (such as LiCoO2, LiMn2O4, LiNi1−xCoxO2 (0<x<1)) have been researched.
As the negative active material of a rechargeable lithium battery, various carbon-based materials such as artificial graphite, natural graphite, and hard carbon have been used, all of which can intercalate and deintercalate lithium ions.
As for the electrolyte, batteries using organic electrolyte solutions provide discharge voltages that are more than twice as high as those of batteries using alkali aqueous solutions. As a result, batteries using organic electrolyte solutions have high energy density. Thus, organic electrolyte solutions are more widely used.
However, it is dangerous to use organic electrolyte solutions because the electrolyte solution may leak and cause explosion and/or ignition at high temperatures. Some attempts to solve this problem have included the development of a flame-retardant electrolyte or the use of an ionic liquid for an electrolyte.
Another attempt to solve the problem resulting from the use of organic electrolyte solutions has been the development of a solid battery, that is, a battery using a solid electrolyte instead of a liquid electrolyte solution.
Solid electrolytes may largely be divided into ceramic-based solid electrolytes and polymer-based solid electrolytes, and the ceramic-based solid electrolytes are divided again into oxide-based solid electrolytes and sulfide-based solid electrolytes.